The present invention relates to a structure of a liquid crystal panel and a liquid crystal display device to a manufacturing method, more particularly it relates to a liquid crystal panel which is built into portable electronic appliances such as notebook type personal computers.
As shown in FIG. 1, the liquid crystal display panel generally has a structure in which liquid crystal display parts such as a lamp reflector 4; an optical guide plate 6; an optical system sheets 8 (like a light collection sheet and light diffusion sheet); and an array cell 10 are stacked on the frame 2. A lamp 12 is attached to the panel, and the parts are affixed to each other by a front bezel 14 formed of metal or plastic. The front bezel 14 is fixed to the frame 2 by a screw or by inserting a bent portion of its flange. Alternately, the parts are assembled with a rear bezel (not shown) onto the opposite side of the frame 2 to the front bezel 14, and the parts from the frame 2 to the array cell 10 are arranged between the front and rear bezels.
Japanese Patent Application Laid Open No. Hesei 7-159,779 discloses a mounting method of a liquid crystal display panel in which a liquid crystal display panel is placed on the upper surface of a back light employing light emission diodes and four corners of the back light and four corners of the liquid crystal panel using a film substrate are subjected to heat to elevate the temperature higher than their melting temperature while subject to pressure whereby both are welded fixedly to each other. Since no fixing members are needed especially, reductions in total weight and thickness of the device and the number of components can be achieved.
Japanese Patent Application laid Open No. Heisei 4-246620 discloses a manufacturing method of a light adjustment liquid crystal panel in which transparent plates are stacked interposing an adhesion sheet on both surface of the liquid crystal sheet. A stacking unit composed of the transparent plates is put in an air bag, and this unit is heated to more than a softening point or a melting point of the adhesion sheets while sucking and exhausting the air from the bag. The liquid crystal sheet and the transparent plate are pressed to each other and united at a low temperature, quickly and at low pressure, with the result that deterioration of the resin matrix in the liquid crystal layer and warp and distortion of the transparent plate are prevented. Moreover, since moisture is removed during heating in vacuum, blistering does not usually occur.
Subject to be Solved by the Invention
Recent years, the demand for note-book type personal computers has been significantly increased from viewpoint of use of the personal computers outside of offices and saving-space. The high performance of miniaturization of the other parts have increased the demand for reduction in thickness and weight of the liquid crystal display panels serving as displays for the computers.
However, in order to attach the members for use in the liquid crystal display panel to each other using the above-described front bezel with requisite force requires frames and front bezels having a certain degree of thickness and weight. When the molding workability of plastics and the sheet metal workability of metals are considered, the thickness of the frame and the front bezel is about 0.5 to 1 mm at the minimum. For the whole of the liquid crystal display panel, a thickness of about 1 to 2 mm is needed merely to fix the members to each other. The liquid crystal display panel is constructed by stacking the front bezel 14, the array cell 10, the optical system sheet tribe 8, the light guide plate 6, the lamp reflector 4, and the frame, resulting in a considerable thickness of the liquid crystal display panel. Depending on circumstances, a rear bezel may be stacked on the frame 2. There are a large number of liquid crystal display panels that have been manufactured as products having thicknesses less than 10 mm. Therefore, the 1 to 2 mm required to fix the members together is considerable. Moreover, since a front bezel made of metal is heavy hindering a reduction in weight of the liquid crystal display panel.
Fixing the members of the liquid crystal display panel employing the front bezel together requires time consuming fitting and/or bending operations. Automatic operations in assembly steps, therefore, tend to be complicated using a large number of steps. Since it is difficult to automatize on the manufacturing lines, using a front bezel is not desirable from the viewpoint of facilitation in assembling the members of the panel.
Moreover, portable electronic appliances are expected to be used under a variety of circumstances, and they are often used in the outdoors and other environments where dust and dirt exists. Atmospheric electricity and the like cause liquid crystal display panel members to adsorb the dust and the dirt, resulting in malfunctions and imperfect image rendering. White spot or black spot defects may occur on the liquid crystal screen under certain circumstances. During use, high temperature coffee may be spilled on the display screen. As a result, the display performance of the liquid crystal display panel might be degraded by water and heat. Moreover, besides the environment these appliances are placed by water and used, it is also necessary to consider the manufacturing environment. Specifically, all of the steps of manufacturing are not always performed in the same factory and manufacturing steps are sometimes conducted in different countries. In cases where sea transport occurs, it is necessary to take the contamination from salt contained in the air into account. Therefore, it is necessary to take counter measures for the salt in the transportation of the products.
Therefore it is an object of the present invention to provide a thin, lightweight a liquid crystal panel where the members of the liquid crystal display panel are assembled without the use of a front bezel and the like.
Another object of the present invention is to provide a method to significantly simplify assembly steps by putting together the members of the liquid crystal display panel without using a front bezel and the like.
Still another object of the present invention is to provide a liquid crystal display panel which has excellent water resistance, dust resistance and salt resistance.
Still a further object of the present invention is to provide a method to perform the positioning of the components of a liquid crystal display panel at time of assembly.
Still further object of the present invention is to provide a method to attach the member of the liquid crystal display panel put together into a unit cover of a liquid crystal display device.
In accordance with the present invention, a liquid crystal display panel part group, composed of a plurality of liquid crystal display panel parts, has a pair of films which are laminated to the liquid crystal display panel parts to hold them together. The liquid crystal display panel part group comprises at least two kinds of liquid crystal display panel parts selected from a group composed of an array cell panel, an optical sheet family, a light guide unit, a lamp reflector, and a lamp. The films binding liquid crystal display panels together can be provided with an opening for exposing the face of the array panel and have through holes for attachment to other parts of the display, such as a cover. Positioning elements are provided to facilitate correct assembly of the parts of the panel part group in the plastic films